The nude of the 19th century was often a tool for anatomical study: an intellectualized and idealized approach to physiognomy.
late 14c., "art of judging characters from facial features," from Old French phizonomie and directly from Late Latin physiognomia, from Greek physiognomia "the judging of a person's nature by his features," from physio- (see physio-) + gnomon (genitive gnomonos) "judge, indicator" (see gnomon). Meaning "face, countenance, features" is from c.1400. Related: Physiognomical.
physiognomy phys·i·og·no·my (fĭz'ē-ŏg'nə-mē, -ŏn'ə-mē)
Facial features, especially when considered as an indicator of character or as a factor in diagnosis.
Estimation of one's character and mental qualities by a study of the face and general bodily carriage.